First determination of the spin-parity of ${\Xi}_{c}(3055)^{+,0}$ baryons

• Main Authors: Albrecht, J, Amey, J. L, Anderlini, L, Ao, D, Da Silva, R. Ataíde, Bachmann, S, Basels, J. M, Behling, N. A, Belyaev, I, Blake, T, Bolzonella, R, Bovill, M, Buonaura, A, Burr, C, Butter, J. S, Caillet, A. C, Ramirez, S. Calderon, Caravaca-Mora, R, Caspary, R, Chahrour, I, Chobanova, V, Chulikov, V, Collins, P, Contu, A, Daniel, J, De Lucia, E, de Vries, J. A, Dembinski, H. -P, Evans, T, Ferrillo, M, Ferro-Luzzi, M, Fini, R. A, Forty, R, Foulds-Holt, D, Frei, C, Gersabeck, E, Giasemis, F. I, Gys, T, Hadavizadeh, T, Hao, L, Henderson, R. D. L, Jiang, Y. J, Juszczak, I, Karacson, M, Khreich, G, Krokovny, P, Lazzeroni, C, Gac, R. Le, Cid, E. Lemos, Lin, T, Lucarelli, C, Lucchesi, D, Lukashenko, V, Mackey, L. M, Maevskiy, A, Malentacca, L, Marchand, J. F, Mariani, E, Santos, D. Martinez, McHugh, N. T, Miao, D, Mokhnenko, S, Morgenthaler, M. P, Mu, Z. M, Nandakumar, R, Nogga, P, Fernandez, J. Novoa, Obraztsov, V, Olocco, M, Ozcelik, O, Panshin, G, Paul, A, Polukhina, N, Rangel, M. S, Raven, G, De Miguel, M. Rebollo, Reich, J, Ricciardi, S, Rudolph, M. S, Sanderswood, I, Saputi, A, Sazak, H, Shekhtman, L, Song, R, Szumlak, T, Tisserand, V, Machado, D. Torres, Trippl, C, Uecker, L. H, Van Hecke, H, van Veghel, M, Sierra, C. Vázquez, Vos, K, White, C, Wu, J, Xiang, Z, Xu, A, Xu, L, Zavertyaev, M, Zhang, J
• Format: Journal Article
• Language: English
• Published: 09.09.2024
• Subjects: Physics - High Energy Physics - Experiment
• DOI: 10.48550/arxiv.2409.05440

The ${{\Xi}_{b}^{0(-)}\to{\Xi}_{c}(3055)^{+(0)}(\to D^{+(0)}{\Lambda}){\pi}^{-}}$ decay chains are observed, and the spin-parity of ${\Xi}_{c}(3055)^{+(0)}$ baryons is determined for the first time. The measurement is performed using proton-proton collision data at a center-of-mass energy of $\sqrt{s}=13\,\text{TeV}$, corresponding to an integrated luminosity of $5.4\,\text{fb}^{-1}$, recorded by the~$\text{LHCb}$ experiment between 2016 and 2018. The spin-parity of the ${\Xi}_{c}(3055)^{+(0)}$ baryons is determined to be $3/2^{+}$ with a significance of more than $6.5\sigma$ ($3.5\sigma$) compared to all other tested hypotheses. The up-down asymmetries of the ${{\Xi}_{b}^{0(-)}\to{\Xi}_{c}(3055)^{+(0)}{\pi}^{-}}$ transitions are measured to be $-0.92\pm0.10\pm0.05$ ($-0.92\pm0.16\pm0.22$), consistent with maximal parity violation, where the first uncertainty is statistical and the second is systematic. These results support the hypothesis that the ${\Xi}_{c}(3055)^{+(0)}$ baryons correspond to the first $D$-wave $\lambda$-mode excitation of the ${\Xi}_{c}$ flavor triplet.